1. Field of the Invention
This invention relates to a control system for a gas-turbine engine, more specifically a control system for a gas-turbine aeroengine used in aircraft.
2. Description of the Related Art
Gas-turbine engine control is performed by using the outputs of a group of sensors installed in the engine to discriminate the engine operating condition and conducting various kinds of control, including calculation and control of the amount of fuel to be supplied, based on the discriminated condition. In determining acceptability or reliability of the sensor outputs, Japanese Laid-open Patent Application No. Hei 6(1994)-050174 teaches a technique that determines or checks whether each sensor output is within an a permissible range, responds to each determination that it is not within the permissible range by resetting the upper and lower limits of the permissible range in accordance with the direction of the deviation, counts the number of times that the inputted value in the next cycle swings up and down within the permissible range within a predetermined time period, and determines that the sensor is faulty when the count value exceeds a predetermined value.
In the gas-turbine engines, in particular in the gas-turbine aeroengines, sensors of the same type are installed at different locations and one among from the sensor outputs is selected to be used in the control. However, the prior art mentioned above only proposes determining the sensor faulty based on the deviation in the permissible range, and discloses nothing on selecting a reliable or appropriate one from among the outputs of the same-type sensors.